[volume-9] Product Ranking with Redis

apps/commerce-api/src/main/java/com/loopers/application/order/OrderEvent.java

@@ -23,16 +23,27 @@ public record OrderCreated(
             Long orderId,
             Long userId,
             Integer originalTotalPrice,
-            Integer discountPrice
+            Integer discountPrice,
+            List<OrderItemInfo> orderItems
     ) {
         public static OrderCreated from(Order order, String loginId) {
+            List<OrderItemInfo> orderItemInfos = order.getOrderItems().stream()
+                    .map(item -> new OrderItemInfo(
+                            item.getProductId(),
+                            item.getProductName(),
+                            item.getPrice(),
+                            item.getQuantity()
+                    ))
+                    .toList();
+
             return new OrderCreated(
                     loginId,
                     order.getOrderKey(),
                     order.getId(),
                     order.getUserId(),
                     order.getOriginalTotalPrice(),
-                    order.getDiscountPrice()
+                    order.getDiscountPrice(),
+                    orderItemInfos
             );
         }
     }

apps/commerce-api/src/main/java/com/loopers/application/product/ProductFacade.java

@@ -4,8 +4,10 @@
 import com.loopers.domain.product.Product;
 import com.loopers.domain.product.ProductService;
 import com.loopers.infrastructure.cache.ProductCacheService;
+import com.loopers.infrastructure.cache.RankingCacheService;
 import com.loopers.support.error.CoreException;
 import com.loopers.support.error.ErrorType;
+import java.time.LocalDate;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
@@ -20,6 +22,7 @@ public class ProductFacade {
     private final ProductService productService;
     private final BrandService brandService;
     private final ProductCacheService productCacheService;
+    private final RankingCacheService rankingCacheService;
 
     public List<ProductInfo> getProducts(ProductCommand.GetProductsCommand command) {
         return productCacheService.getProductList(
@@ -57,12 +60,30 @@ public List<ProductInfo> getProducts(ProductCommand.GetProductsCommand command)
     }
 
     public ProductInfo getProduct(Long productId) {
-        return productCacheService.getProduct(productId, () -> {
+        ProductInfo productInfo = productCacheService.getProduct(productId, () -> {
             Product product = productService.findProductById(productId)
                     .orElseThrow(() -> new CoreException(ErrorType.NOT_FOUND, "상품을 찾을 수 없습니다."));
             String brandName = brandService.findBrandNameById(product.getBrandId());
             return ProductInfo.from(product, brandName);
         });
+
+        Long rank = rankingCacheService.getProductRank(LocalDate.now(), productId);
+
+        if (rank != null) {
+            return new ProductInfo(
+                    productInfo.id(),
+                    productInfo.name(),
+                    productInfo.brandId(),
+                    productInfo.brandName(),
+                    productInfo.price(),
+                    productInfo.likeCount(),
+                    productInfo.stock(),
+                    productInfo.createdAt(),
+                    rank
+            );
+        }
+
+        return productInfo;
     }
 }
 

apps/commerce-api/src/main/java/com/loopers/application/product/ProductInfo.java

@@ -11,7 +11,8 @@ public record ProductInfo(
         Integer price,
         Integer likeCount,
         Integer stock,
-        ZonedDateTime createdAt
+        ZonedDateTime createdAt,
+        Long rank
 ) {
     public static ProductInfo from(Product product, String brandName) {
         return new ProductInfo(
@@ -22,7 +23,22 @@ public static ProductInfo from(Product product, String brandName) {
                 product.getPrice().getPrice(),
                 product.getLikeCount().getCount(),
                 product.getStock().getQuantity(),
-                product.getCreatedAt()
+                product.getCreatedAt(),
+                null
+        );
+    }
+
+    public static ProductInfo from(Product product, String brandName, Long rank) {
+        return new ProductInfo(
+                product.getId(),
+                product.getName(),
+                product.getBrandId(),
+                brandName,
+                product.getPrice().getPrice(),
+                product.getLikeCount().getCount(),
+                product.getStock().getQuantity(),
+                product.getCreatedAt(),
+                rank
         );
     }
 }

apps/commerce-api/src/main/java/com/loopers/application/ranking/RankingCommand.java

@@ -0,0 +1,14 @@
+package com.loopers.application.ranking;
+
+import java.time.LocalDate;
+
+public class RankingCommand {
+
+    public record GetDailyRankingCommand(
+            LocalDate date,
+            int page,
+            int size
+    ) {
+    }
+
+}

apps/commerce-api/src/main/java/com/loopers/application/ranking/RankingFacade.java

@@ -0,0 +1,76 @@
+package com.loopers.application.ranking;
+
+import com.loopers.domain.brand.BrandService;
+import com.loopers.domain.product.Product;
+import com.loopers.domain.product.ProductService;
+import com.loopers.domain.ranking.Ranking;
+import com.loopers.domain.ranking.RankingService;
+import java.util.Objects;
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.stereotype.Component;
+
+import java.util.List;
+import java.util.Map;
+import java.util.stream.Collectors;
+
+@RequiredArgsConstructor
+@Component
+@Slf4j
+public class RankingFacade {
+
+    private final RankingService rankingService;
+    private final ProductService productService;
+    private final BrandService brandService;
+
+    public RankingInfo getDailyRanking(RankingCommand.GetDailyRankingCommand command) {
+        List<Ranking> rankings = rankingService.getRanking(
+                command.date(),
+                command.page(),
+                command.size()
+        );
+
+        if (rankings.isEmpty()) {
+            return new RankingInfo(List.of());
+        }
+
+        List<Long> productIds = rankings.stream()
+                .map(Ranking::productId)
+                .collect(Collectors.toList());
+
+        List<Product> products = productService.findProductsByIds(productIds);
+        Map<Long, Product> productMap = products.stream()
+                .collect(Collectors.toMap(Product::getId, product -> product));
+
+        List<Long> brandIds = products.stream()
+                .map(Product::getBrandId)
+                .distinct()
+                .collect(Collectors.toList());
+        Map<Long, String> brandNameMap = brandService.findBrandNamesByIds(brandIds);
+
+        List<RankingInfo.RankingItemInfo> rankingItemInfos = rankings.stream()
+                .map(ranking -> {
+                    Product product = productMap.get(ranking.productId());
+                    if (product == null) {
+                        log.warn("랭킹에 있는 상품이 DB에 존재하지 않음: productId={}", ranking.productId());
+                        return null;
+                    }
+
+                    String brandName = brandNameMap.getOrDefault(product.getBrandId(), "알 수 없음");
+
+                    return new RankingInfo.RankingItemInfo(
+                            ranking.productId(),
+                            product.getName(),
+                            brandName,
+                            product.getPrice().getPrice(),
+                            product.getLikeCount().getCount(),
+                            ranking.rank(),
+                            ranking.score()
+                    );
+                })
+                .filter(Objects::nonNull)
+                .collect(Collectors.toList());
+
+        return new RankingInfo(rankingItemInfos);
+    }
+}

apps/commerce-api/src/main/java/com/loopers/application/ranking/RankingInfo.java

@@ -0,0 +1,18 @@
+package com.loopers.application.ranking;
+
+import java.util.List;
+
+public record RankingInfo(
+        List<RankingItemInfo> items
+) {
+    public record RankingItemInfo(
+            Long productId,
+            String productName,
+            String brandName,
+            Integer price,
+            Integer likeCount,
+            Long rank,
+            Double score
+    ) {
+    }
+}

apps/commerce-api/src/main/java/com/loopers/domain/brand/Brand.java

@@ -4,6 +4,7 @@
 import jakarta.persistence.Column;
 import jakarta.persistence.Entity;
 import jakarta.persistence.Table;
+import lombok.Builder;
 import lombok.Getter;
 
 @Entity
@@ -17,4 +18,19 @@ public class Brand extends BaseEntity {
     @Column(nullable = false)
     private String description;
 
+    public Brand() {
+    }
+
+    @Builder
+    public Brand(String name, String description) {
+        this.name = name;
+        this.description = description;
+    }
+
+    public static Brand createBrand(String name, String description) {
+        return Brand.builder()
+                .name(name)
+                .description(description)
+                .build();
+    }
 }

apps/commerce-api/src/main/java/com/loopers/domain/product/ProductRepository.java

@@ -15,4 +15,6 @@ public interface ProductRepository {
 
     List<Product> findProductsByLikesDesc(Long brandId, int page, int size);
 
+    List<Product> findProductsByIds(List<Long> productIds);
+
 }

apps/commerce-api/src/main/java/com/loopers/domain/product/ProductService.java

@@ -53,6 +53,11 @@ public List<Product> findProductsByLikesDesc(Long brandId, int page, int size) {
         return productRepository.findProductsByLikesDesc(brandId, page, size);
     }
 
+    @Transactional(readOnly = true)
+    public List<Product> findProductsByIds(List<Long> productIds) {
+        return productRepository.findProductsByIds(productIds);
+    }
+
     @Transactional
     public Product increaseLikeCount(Long productId) {
         Product product = productRepository.findProductById(productId)

apps/commerce-api/src/main/java/com/loopers/domain/ranking/Ranking.java

@@ -0,0 +1,8 @@
+package com.loopers.domain.ranking;
+
+public record Ranking(
+        Long productId,
+        Long rank,
+        Double score
+) {
+}

apps/commerce-api/src/main/java/com/loopers/domain/ranking/RankingItem.java

@@ -0,0 +1,8 @@
+package com.loopers.domain.ranking;
+
+public record RankingItem(
+        Long productId,
+        Double score
+) {
+}
+

apps/commerce-api/src/main/java/com/loopers/domain/ranking/RankingService.java

@@ -0,0 +1,37 @@
+package com.loopers.domain.ranking;
+
+import com.loopers.infrastructure.cache.RankingCacheService;
+import lombok.RequiredArgsConstructor;
+import org.springframework.stereotype.Service;
+
+import java.time.LocalDate;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.stream.IntStream;
+
+@RequiredArgsConstructor
+@Service
+public class RankingService {
+
+    private final RankingCacheService rankingCacheService;
+
+    public List<Ranking> getRanking(LocalDate date, int page, int size) {
+        long start = (long) (page - 1) * size;
+        long end = start + size - 1;
+
+        List<RankingItem> rankingItems = rankingCacheService.getRankingRange(date, start, end);
+
+        if (rankingItems.isEmpty()) {
+            return new ArrayList<>();
+        }
+
+        return IntStream.range(0, rankingItems.size())
+                .mapToObj(i -> {
+                    RankingItem item = rankingItems.get(i);
+                    long rank = start + 1 + i;
+                    return new Ranking(item.productId(), rank, item.score());
+                })
+                .toList();
+    }
+}
+